George Gershwin, born in 1998, was one of America's greatest composers. He published his first song when he was eighteen years old. During the next twenty years he wrote more than five hundred songs.

Many of Gershwin's songs were first written for musical plays performed in theatres in New York City. These plays were a popular form of entertainment in the 1920s and 1930s. Many of his songs have remained popular as ever. Over the years they have been sung and played in every possible way — from jazz to country.

    In the 1920s there was a debate in the United States about jazz music. Could jazz, some people asked, be considered serious music? In 1924 jazz musician and orchestra leader Paul Whiteman decided to organize a special concert to show that jazz was serious music. Gershwin agreed to compose something for the concert before he realized he had just a few weeks to do it. And in that short time, he composed a piece for piano and orchestra which he called Rhapsody in Blue. Gershwin himself played the piano at the concert. The audience were thrilled when they heard his music. It made him world-famous and showed that jazz music could be both serious and popular.

    In 1928, Gershwin went to Paris. He applied to study composition (作曲)with the well-known musician Nadia Boulanger, but she rejected him. She was afraid that classical study would ruin his jazz-influenced style. While there, Gershwin wrote An American in Paris. When it was first performed, critics (评论家)were divided over the music. Some called it happy and full of life, to others it was silly and boring. But it quickly became popular in Europe and the United States. It still remains one of his most famous works.

    George Gershwin died in 1937, just days after doctors learned he had brain cancer. He was only thirty-nine years old. Newspapers all over the world reported his death on their front pages. People mourned the loss of the man and all the music he might have still written.

Human speech contains more than 2, 000 different sounds, from the common "m" and "a" to the rare clicks of some southern African languages. But why are certain sounds more common than others? A ground-breaking, five-year study shows that diet-related changes in human bite led to new speech sounds that are now found in half the world's languages.

More than 30 years ago, the scholar Charles Hockett noted that speech sounds called labiodentals, such as "f" and "v", were more common in the languages of societies that ate softer foods. Now a team of researchers led by Damián Blasi at the University of Zurich, Switzerland, has found how and why this trend arose.

They discovered that the upper and lower front teeth of ancient human adults were aligned (对齐), making it hard to produce labiodentals, which are formed by touching the lower lip to the upper teeth. Later, our jaws changed to an overbite structure(结构), making it easier to produce such sounds.

The team showed that this change in bite was connected with the development of agriculture in the Neolithic period. Food became easier to chew at this point. The jawbone didn't have to do as much work and so didn't grow to be so large.

Analyses of a language database also confirmed that there was a global change in the sound of world languages after the Neolithic age, with the use of "f" and "v" increasing remarkably during the last few thousand years. These sounds are still not found in the languages of many hunter-gatherer people today.

This research overturns the popular view that all human speech sounds were present when human beings evolved around 300, 000 years ago. "The set of speech sounds we use has not necessarily remained stable since the appearance of human beings, but rather the huge variety of speech sounds that we find today is the product of a complex interplay of things like biological change and cultural evolution," said Steven Moran, a member of the research team.

According to the Solar Energy Industry Association, the number of solar panels installed(安装)has grown rapidly in the past decade, and it has to grow even faster to meet climate goals. But all of that growth will take up a lot of space, and though more and more people accept the concept of solar energy, few like large solar panels to be installed near them.

Solar developers want to put up panels as quickly and cheaply as possible, so they haven't given much thought to what they put under them. Often, they'll end up filling the area with small stones and using chemicals to control weeds. The result is that many communities, especially in farming regions, see solar farms as destroyers of the soil.

"Solar projects need to be good neighbors," says Jordan Macknick, the head of the Innovative Site Preparation and Impact Reductions on the Environment(InSPIRE)project. "They need to be protectors of the land and contribute to the agricultural economy." InSPIRE is investigating practical approaches to "low-impact" solar development, which focuses on establishing and operating solar farms in a way that is kinder to the land. One of the easiest low-impact solar strategies is providing habitat for pollinators(传粉昆虫).

Habitat loss, pesticide use, and climate change have caused dramatic declines in pollinator populations over the past couple of decades, which has damaged the U.S. agricultural economy. Over 28 states have passed laws related to pollinator habitat protection and pesticide use. Conservation organizations put out pollinator-friendliness guidelines for home gardens, businesses, schools, cities—and now there are guidelines for solar farms.

Over the past few years, many solar farm developers have transformed the space under their solar panels into a shelter for various kinds of pollinators, resulting in soil improvement and carbon reduction. "These pollinator-friendly solar farms can have a valuable impact on everything that's going on in the landscape," says Macknick.